1. Field of the Invention
This invention relates to a speech recognition apparatus and speech recognition method for recognizing the speech inputted by a user to control an apparatus, and more particularly to an improvement in speech input operation.
2. Description of the Related Art
As car navigation for designating a desired location to set a destination and search a route from a current position of a vehicle to the destination and displaying it together with a map including the current position on the display thereby provide a guide to the destination, there is recent advent of those having speech-operated functions adapted to recognize the input speeches of the user by use of a mike thus enabling various operations through recognized speeches.
The location designation in car navigation with speech operation is performed by sequentially speaking and inputting speeches in kind of the facilities existing in a subject of location such as schools, hospitals and stations or location addresses, in response to a guidance message and finally speaking a location native name. In this manner, recognition rate is secured by setting subject-of-recognition words/phrases in each speech and the subsequent narrowing down of the subject-of-recognition words/phrases.
One example of a setting procedure of a designation will be explained. In the initial stage, the speech recognition system side is set with a “Control Command Dictionary” as a control-command subject-of-recognition words/phrases for car-navigating operation. By user's speaking of a command “Set Designation”, an intention of setting a route to the destination is conveyed to the system.
Subsequently, there is a need to designate a concrete location of a destination. However, because the locations prepared on the car navigation is huge, designation with a once speech operation is not practical from a viewpoint of limitation in recognition rate or memory size. Accordingly, narrowing down is made for the number of locations to be designated.
First, narrowing down is made in the kind of facilities existing in the subject of location (hereinafter referred to as genre). The speech recognition dictionary is replaced from a “Control Command Dictionary” to a “Genre Name Dictionary”, wherein (1) a guidance message “Genre Name Please” is outputted to prompt the user to speak a genre. In response to this, if the user (2) speaks, for example, “Educational Facility” as a genre, the speech recognition system recognizes the speech. In order to designate a further detailed sub-genre belonging to the educational facilities for further narrowing down, the speech recognition dictionary is replaced from the “Genre Name Dictionary” to a “Sub-genre Name Dictionary Belonging to Education Facility” and (3) a guidance message “Next Genre Name Please” is outputted to prompt the user to speak a sub-genre name. In response to this, if the user (4) speaks, for example, “University and College” as a sub-genre, the speech recognition system recognizes the speech.
If the sub-genre is established, narrowing down is further made in region. The speech recognition dictionary is replaced from the “Sub-genre Name Dictionary” to a “Metropolis-and-District Name Dictionary” and (5) a guidance message “Metropolis or District Name Please” to prompt the user to speak a metropolis-or-district name. In response to this, if the user (6) speaks, for example, “Tokyo Metropolis”, the speech recognition system recognizes the speech as “Tokyo Metropolis”. In the case that the sub-genre is “University and College” and the metropolis-or-district name is “Tokyo Metropolis”, the system side is previously determined to execute a further detailed designation of a city/ward/town/village name. For this reason, the speech recognition dictionary is replaced from the “Metropolis-and-District Name Dictionary” to a “Tokyo-Metropolis City/Ward/Town/Village Name Dictionary” and (7) a guidance message “City/Ward/Town/Village Name Please” is outputted to prompt the user to speak a city/ward/town/village name. In response to this, if the user (8) speaks, for example, “Shinjyuku Ward”, the speech recognition system recognizes the speech.
The system side replaces the speech recognition dictionary from the “Tokyo-Metropolis City/Ward/Town/Village Name” to a “University-and-College Name Dictionary” having facility names as subjects of recognition belonging to the university and college existing in Shinjyuku ward, Tokyo and (9) a guidance message “Name Please” is outputted to prompt the user to speak a concrete name of the designated location. Herein, if the user speaks “OO University (or College)”, the speech recognition system recognizes it and the navigator sets the OO University (or College) as a destination. In this manner, the subject-of-location conditions are inputted to reduce the number of subjects of location thereby inputting the native names of the narrowed subjects of location.
In the meanwhile, because the foregoing narrowing conditions and condition-inputting order are previously fixed, there occurs a situation that a condition not known by the user be prompted to input. On that occasion, the user if cannot respond to the prompt is not allowed to proceed to the subsequently continuing steps for inputting narrowing conditions. Consequently, the designation of location must be given up without speaking a concrete name of an objective subject of location. Thus, there has been difficulty in operationality and responsibility.